Investigation of Testosterone, Androstenone, and Estradiol Metabolism in HepG2 Cells and Primary Culture Pig Hepatocytes and Their Effects on 17βHSD7 Gene Expression

Abstract

Steroid metabolism is important in various species. The accumulation of androgen metabolite, androstenone, in pig adipose tissue is negatively associated with pork flavor, odour and makes the meat unfit for human consumption. The 17β-hydroxysteroid dehydrogenase type 7 (17βHSD7) expressed abundantly in porcine liver, and it was previously suggested to be associated with androstenone levels. Understanding the enzymes and metabolic pathways responsible for androstenone as well as other steroids metabolism is important for improving the meat quality. At the same time, metabolism of steroids is known to be species- and tissue-specific. Therefore it is important to investigate between-species variations in the hepatic steroid metabolism and to elucidate the role of 17βHSD7 in this process. Here we used an effective methodological approach, liquid chromatography coupled with mass spectrometry, to investigate species-specific metabolism of androstenone, testosterone and beta-estradiol in HepG2 cell line, and pig cultured hepatocytes. Species- and concentration-depended effect of steroids on 17βHSD7 gene expression was also investigated. It was demonstrated that the investigated steroids can regulate the 17βHSD7 gene expression in HepG2 and primary cultured porcine hepatocytes in a concentration-dependent and species-dependent pattern. Investigation of steroid metabolites demonstrated that androstenone formed a 3′-hydroxy compound 3β-hydroxy-5α-androst-16-ene. Testosterone was metabolized to 4-androstene-3,17-dione. Estrone was found as the metabolite for β-estradiol. Inhibition study with 17βHSD inhibitor apigenin showed that apigenin didn’t affect androstenone metabolism. Apigenin at high concentration (50 µM) tends to inhibit testosterone metabolism but this inhibition effect was negligible. Beta-estradiol metabolism was notably inhibited with apigenin at high concentration. The study also established that the level of testosterone and β-estradiol metabolites was markedly increased after co-incubation with high concentration of apigenin. This study established that 17βHSD7 is not the key enzyme responsible for androstenone and testosterone metabolism in porcine liver cells.

The Association between the Levels of Serum Ferritin and Sex Hormones in a Large Scale of Chinese Male Population

“…For testosterone, as we all knew it was one of the most active androgens and mainly bounded to SHBG and albumin. However, only free testosterone was bioactive [35], [36]. So far we know that testosterone was with important functions of regulatory [37] and also related to many diseases, such as anemia, metabolic syndrome and the iron stage [18], [36].…”

“…However, only free testosterone was bioactive [35], [36]. So far we know that testosterone was with important functions of regulatory [37] and also related to many diseases, such as anemia, metabolic syndrome and the iron stage [18], [36]. Furthermore, previous studies had also showed that the levels of total testosterone and SHBG were negatively associated with metabolic syndrome [16] while the levels of serum ferritin was in a positive association with metabolic syndrome [3].…”

Interferon-Inducible Cholesterol-25-Hydroxylase Inhibits Hepatitis C Virus Replication via Distinct Mechanisms

“…The residue was reconstituted with 0.5 mL of acetonitrile and 0.5 mL of water and analyzed by LC-MS/MS with ESI+ ion source (API 5000, Applied Biosystems, ON, Canada). The instrument procedure follows the description 41 .…”

Metabolism of Androstenone, 17β-Estradiol and Dihydrotestosterone in Primary Cultured Pig Hepatocytes and the Role of 3β-Hydroxysteroid Dehydrogenase in This Process

“…Primary pig hepatocytes were isolated from Large White male pigs (3–5 days old) using procedure described by Chen et al [13] . The experimental protocol for using animals was approved by the Animal Ethics Committee of the China Agricultural University, Beijing, China (permission number: 2011-11-23-1).…”

“…It can be either irreversibly converted to estrogens by aromatase, or can be transformed to other active form such as dihydrotestosterone [9] . Testosterone metabolism in pig hepatocytes has been studied previously and it was established that 4-androstene-3,17-dione was its main metabolite [13] . 17β-Estradiol and dihydrotestosterone are also known as bioactive steroids of the endocrine systems.…”